Pump



Aug. 29, 1961 P. v. wYsoNG, JR

PUMP

4 Sheets-Sheet 1 Filed May 8, 1958 www MTM M. w m m I9 TTOFIVfY ug- 29, 1961 P. v. wYsoNG, JR 2,997,962

PUMP

Filed May 8, 1958 4 Sheets-Sheet 2 Y IN VENTOR. BY///W/yc/g Aug. 29, 1961 P. v. wYsoNG, JR

PUMP

4 Sheets-Sheet 3 Filed May 8, 1958 Aug. 29, 1961 P. v. wYsoNG, JR

PUMP

4 Sheets-Sheet 4.

Filed May 8, 1958 United States 'Patent This invention relates to uid pumps and more particularly pertains to a multi-cylinder pump suited for high speed operation.

Although the pump herein has a wide field of application, it was developed with a view toward its use in automotive vehicles to provide uid pressure for the operation of various accessories, e.g., power steering apparatus, power brakes, trunk lift mechanism, etc. So applied, it may with advantage be employed to serve an accumulator from which the several accessories draw or it may be operated to directly supply an accessory without the intervention of an accumulator.

An important advantage of the instant pump resides in the fact that it may be powered directly by the armature shaft of the generator component of the vehicle electrical system.

The principal objects of the invention being implicit in the foregoing, the same will be specically described in terms of a preferred embodiment thereof illustrated by the accompanying drawings wherein:

FIGURE l is a view showing parts of the pump in longitudinal section;

FIGURE 2 is a view on the line 2-2 in FIGURE l;

FIGURE 3 is a view on the line 3-3 in FIGURE 2;

FIGURE 4 is a section on the line 4--4 in FIGURE l;

FIGURE 5 is a section on the line 5 5 in FIGURE 1;

FIGURE 6 is a view on the line 6-.6 in FIGURE l; and

FIGURE 7 is a section on the line 7-7 in FIGURE 1.

Referring first to FIGURE l, a drive shaft 3 having an eccentric lobe 3a rotates in outboard solid bearings bored in the pump housing 1 and cover 2. Axial holes 4 and 5 are drilled in the shaft 3 to provide suction and discharge passages respectively. Two balance weights 6 (see also FIG. 5) are pinned to the shaft 3 on either side of the cylinder block 12 by roll pins 7. The outside faces of lthe balance weights shoulder against the cover 2 and housing 1, the axial thrust loads thus being transmitted to the housing members.

Two grooves 8 and 9 separated axially will be seen formed in the eccentric lobe 3a of the shaft 3. Groove 8 is a suction groove, the same being connected radially to suction passage 4 via a radial passage 10. Groove 9 is a pressure groove and is connected to the pressure passage 5 by a radial passage 11.

The cylinder block 12 has a bearing sleeve 13, desirably formed of aluminum alloy, which runs on the eccentric lobe 3a. In the particular embodiment, seven cylinders 14 (FIGURE 4) are formed in the block 12, these cylinders being equally spaced with their center lines parallel to the center line of the central bore in the block.

Each cylinder 14 contains a spring 15, a pair of plugs 16 and two balls 17. A hole 49 is provided in the wall of each cylinder in axial alignment with the groove 8. Similarly, each cylinder has in the wall thereof a hole 50 in axial alignment with the groove 9.

A cam ring 18 is mounted in the cover 2, while another such ring is carried in the housing 1. The axes of the cam rings lie along the major axis of the shaft 3, with the ramp faces 18a in contact with the balls 17. On rotation of shaft 3, a drag mechanism made up of a pin having 'a ball head 19 carried in a plug threaded Patented Aug. 29, 1961 ICC 2 into the housing 1 and a shank portion 19a slidably accommodated (FIGURE 4) in a hole in the block 12, so constrains the block that the movement thereof is of an oscillating or nutating character.

Two annular retainers 32 serve at assembly to prevent dislodgement of the balls 17 and the associated plugs and springs. Incident to the assembly operation, that is, upon addition of the cover 2, following locating of the cam rings 18 and balance weights 6, the balls 17 are forced toward each other so that they leave their seats on the retainers, which are not thereafter functional.

Shaft 3 has therein radial passages 20 providing a connection between the pressure passage 5 and an annular groove 21 formed in the cover 2. A passage 22 including a restriction 51 connects the annular groove 21 to the discharge port 23, while passage 24 in the cover 2 extends from the annular groove 21 to a bore 24a in the cover. Within the latter bore is disposed a by-pass valve spool 25. -A passage 26 opens the bore 24a to the discharge port 23.

As shown, spool 25 is loaded by a spring 27 in a direction toward a backing plug 38. Within the spool 25 is confined a conventional lrelief valve assembly 28 consisting essentially of a spring-loaded ball 28a normally closing oi radial passages 28b to passage 55. A passage 29 (see also FIGURE 3) extends from bore 24a to make connection with a passage 30 opening to the cavity or chamber 37 (note FIG. l) at the end of the shaft 3. Passage 30 will be seen as having communication with passage 31 opening to the reservoir 40, which encompasses the pump housing 1 and the parts therein contained.

Reverting to FIGURE 1, a threaded member 33 carry! ing a seal 34 will be observed as closing od the pressure passage 5 in the shaft 3. Such member 33 also serves in the attachment of a drive pulley 35. A key 53 is used in the making of the connection between the pulley and shaft, which is sealed about its outer diameter inward of the pulley by a lip seal 36 carried in the pump cover 2. The pump, of course, may be driven otherwise than through a pulley.

The left-hand portion of the reservoir 40 is shown attached to two lugs 57 which, with the wall of the reservoir, form the previously mentioned cavity or chamber 37. An O-ring seal 41 is accommodated in a recess in the cover 2, being retained in such recess by the reservoir wall. The bolts 42, through which the reservoir is secured to the lugs 57, extend through sealing washers which may with advantage be formed of soft copper. Bolts 42 also serve to make fast a mounting bracket 43 by means of which the pump assembly is secured on installation thereof.

Reservoir 40 is lled with fluid through a cap and ller tube assembly 45. Fluid returned to the reservoir is introduced thereinto via a tube 47 which carries at its end within the reservoir a filter 48. A dip stick 52, i11- cluded in the assembly 45, may be removed to indicate the level of the fluid in the reservoir.

.A passage 54 in the boss portion of the cover 2 allows for recovery of oil bleeding from groove 21 into the cavity in which the seal 36 is located. A vent 58 in the housing 12 serves to prevent any pressure build-up in the pump cavity.

Operation With shaft 3 rot-ating, the eccentric lobe 3a causes the cylinder block 12 to nutate in a path, approximately circular, whose diameter .is twice the eccentricity. The drag means constituted of the pin 19, 19a, as previously indicated, brings about the nutating or oscillating motion of the block, which would otherwise tend to rotate with the eccentric lobe. As the block 12 nutates, balls 17 ride up and down the'ramp surfaces 18a, this action, of course,

being accompanied by in and out movement of the balls in the cylinders. When the balls move inward, the volume of the cylinder is decreased with discharge of Huid-note the lower cylinder in FIGURE 1'. Conversely,when thej the free volume of the cylinder and thus increase the compression ratio, making for ready starting of the pump;

With the pump in operation, uid from the cavity 37, which is open to the reservoir 40 via passage 31 (FIG- URE 3), flows through the passage 4 into the suction groove 8 via hole 10. y Any cylinder 14 whose suction con-k necting hole or port 49 is open to groove 8 thus draws in fluid, the groove being so circumferentially located on the eccentric lobe 3a that when a cylinder port 49 is in registry with the groove the balls in the cylinder are in suction phase, that is, the balls are moving outwardly. A supercharg'ing effect aiding the filling of the cylinders results through the centrifugal force imparted to the uid by the rotation of the shaft 3. Also, since the level of the iiuid in the reservoir 40 is above the passage 4, a stat-ic head is provided which aids in the filling of the cylinders. As the balls in a cylinder start to move inwardly'as is the case on their discharge stroke, the eccentric lobe 3a blocks the cylinder port 49 while the groove 9 in the lobe` gins registry with the cylinder port 50. The discharged' iiuid follows passageways and 20 to the annular groove 2 1 which, as before noted, has communication with the discharge port 23 (FIGURE 6) via the restriction 51 andthe passage 22. Restriction 51 determines the discharge' .A portion off the fluid discharge is conveyed fromU groove 21 via passage 24 to the bore 24a where it reacts against the left-hand end of the by-pass spool or plunger 25. Depending upon the magnitude of the discharge pressure, the spool may be forced rightwardly against the resistance of the spring 27 so that passageway 24 becomes open to passage 29, which communicates via passages 30 and 31 (FIGURE 3) with the reservoir. With the passages 24 and 29 interconnected the pump, o f course, idles until the pressure of the iluid reacting against the left-hand end of the spool decreases to a predetermined value. Should the system pressure, 'i.e., the 'pressure at 23l (FIGURE 6) become excessive, the fluid entering behind the ball 28a via passages 26 and 55 displaces the ball, port 23 thus becoming connected to the reservoir return port 29 via the radial passages 28h. Once the system pressure becomes reduced to normal, ball 28 is restored to itsY shown position by thev action of the associated spring. l

What is claimed is:

v1. A pump structure comprising a housing, a block within said housing providing a plurality of open-ended cylinders each having an inlet port and a discharge port inthe wall thereof, a pair of pistons confined within each said cylinder, one at each open end thereof, yieldable means within each cylinder loading the corresponding pistons outwardly, cam means within said housing having ramp surfaces engaging said pistons outwardly of said cylinders, eccentric drivemeans within said cylinder block,- and drag means carried by said housing and including a portion operably connected to said block whereby on 'rotation of said eccentric drive means said block is caused to nutate with reciprocation of said pistons in their respective cylinders, as induced by said surfaces.

2. A pump structure comprising a housing, a block Within said housing providing a plurality of open-ended cylinders disposed with their axes paralleling the axis of the block, each of said cylinders having an inlet port and an outlet port in the wall thereof, a pair of pistons confined within each said cylinder, one at each open end thereof, yieldable means within each cylinder loading the corresponding pistons outwardly, cam means within said housing having ramp surfaces' engaging said pistons outwardly of said cylinders, eccentric drive means within said cylinder block, and drag means carried by said hous-- ing and including a portion operably connected to said block whereby on rotation of said eccentricdrive means said block is caused to nutate with reciprocation of said pistons in their respective cylinders, as induced by said surfaces. Y

3. A pump structure comprising a housing, ablock within said housing providing a plurality of open-ended cylinders disposed withtheiraxes paralleling the axis of the block, each of said cylinders havingan inlet port and an outlet port in the wall thereof, a pai-rof balls confined within each said cylinder, one at each open end. thereof, yieldable means within each said cylinder loading. the corresponding balls outwardly through a pair of plug elements, cam means carried by said housing and having ramp surfaces engaging .said balls outwardly of said cylinders, eccentric drive means within said cylinder bloclo` cylinders, as induced by said-surfaces.4

and drag means carried by said housing and including a portion operably connected to said block whereby on rota-k tion of said Veccentric drive means said block is caused to. nutate with reciprocation of said balls in their respective.

4. A pump structure comprising ya housing, a block with-l in said housing providing a plurality of radially arranged open-ended cylinders disposed with their axes parallelingthe axis. of the block, each of said cylinders-having an inlet port and an outlet' port in the wall thereof, a pairof pistons confined Within each said cylinder, one atv each open end thereof, a spring within each said cylinder loading the corresponding pistons outwardly, cam means carried by said-housing and having ramp surfaces engaging said pistons outwardly of said cylinders, eccentric drive means within said cylinder block, and drag means` carried by said housing and including a portion operablyV` connected to said blocklwhereby on rotationl of said eccentric drive means said block is caused to nutate with reciprocation of said pistons in their respective cylinders, as induced by said surfaces. y v A 5. A pump structure comprising a housing, a block within said housing providing a plurality of radiallyv arranged open-ended cylinders disposed with their axes paralleling the -axis of the block, each of saidcylindersI having an inlet port and an outlet port in the-wall thereof,v a pair of balls conlinedwithin each said cylinder, one atV each open-endl thereof, a spring within each said cylinder loading the corresponding balls outwardly througha pair of plug elements operating to decrease the free volume ofthecylinder thereby to increase the compression ratiol when the pump is initially-started, cam means Vcarried by'said housing and having ramp surfaces engaging said balls outwardly of said cylinders, eccentric drive means within said cylinderblock, and drag means carried by said housing and including aV portion operably connectedI to said block whereby on rotation of said eccentric drive means said, block is caused to nutate with reciprocation of said balls in their respective cylinders, as inducedY by said surfaces. l

6.Y A pump structure comprising a housing-'a blockr within said housing -'providing a plurality of radially "arranged open-ended cylinders disposed with 'their axes' paralleling the axis of the Iblock, each 'said cylinder having intake and discharge ports in the wall thereof, a pair: of balls confined within each said cylinder, one-at each open en'd thereof, yieldable means 'within each said cylinder loading the corresponding balls outwardly through a pair of plug elements, a pair of cam rings carried by said; housing and spaced apart a distance set by the length of said cylinder, said cam rings having ramp surfaces engaging said balls, a drive shaft extending' into saidVV housing and carrying an eccentric lobe surrounded by said cylinder block, said shaft having intake and discharge passages therein registering with said ports in operation of the pump, and drag means carried by said housing and including a portion operably connected to said block whereby on rotation of said shaft said block is caused -toy nutate with reciprocation of said balls in their respective cylinders, as induced by said surfaces.

7. A pump structure comprising `a housing, a block within said housing providing a plurality of open-ended cylinders each having an inlet port yand an `outlet port in the wall thereof, a pair of pistons confined within each said cylinder, one at each open end thereof, yieldable means within each cylinder loading the corresponding pistons outwardly, cam means within said housing having ramp surfaces engaging said pistons outwardly of said cylinders, eccentric drive means Within said cylinder block and a ball-headed pin seated by said housing with the shank portion thereof slidably `accommodated in `a hole formed in said block, whereby on rotation of said eccentric drive means said block is caused to nutate with reciprocation of said pistons in their respective cylinders, as induced by said surfaces.

8. A pump structure comprising a housing, a block within said housing providing a plurality of open-ended cylinders, each said cylinder having intake and discharge ports in the Wall thereof, a pair of pistons conned within including a portion operably connected to said block whereby on rotation of said shaft said block is caused to nutate with reciprocation of said pistons in their respective cylinders, as induced by said surfaces.

9. A pump structure according to claim 8 wherein said drag means takes the lform of a pin having a ball head seating in said housing and a shank portion slidably accommodated in a hole in said Iblock.

References Cited in the file of this patent UNITED STATES PATENTS 2,768,582 Klessig et al Oct. 30, 1956 2,818,813 Pettibone et al. Jan. 7, 1958 2,829,599 Jones Apr. 8, 1958 2,839,003 Thrap et al June 17, 1958 FOREIGN PATENTS 823.828 Germany Dec. 6, 1951 

